From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: [PATCH] i2c: Prevent runtime suspend of adapter when Host Notify is required Date: Thu, 2 May 2019 16:32:51 +0100 Message-ID: <20190502153251.GG81578@ediswmail.ad.cirrus.com> References: <20190430142322.15013-1-jarkko.nikula@linux.intel.com> <20190430155637.1B45E21743@mail.kernel.org> <7f989564-e994-5be6-02da-2838639efe59@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <7f989564-e994-5be6-02da-2838639efe59@linux.intel.com> Sender: stable-owner@vger.kernel.org To: Jarkko Nikula Cc: Sasha Levin , linux-i2c@vger.kernel.org, Wolfram Sang , stable@vger.kernel.org List-Id: linux-i2c@vger.kernel.org On Thu, May 02, 2019 at 03:32:24PM +0300, Jarkko Nikula wrote: > On 4/30/19 6:56 PM, Sasha Levin wrote: > >This commit has been processed because it contains a "Fixes:" tag, > >fixing commit: c5eb1190074c PCI / PM: Allow runtime PM without callback functions. > > > >The bot has tested the following trees: v5.0.10, v4.19.37. > > > >v5.0.10: Build OK! > >v4.19.37: Failed to apply! Possible dependencies: > > 6f108dd70d30 ("i2c: Clear client->irq in i2c_device_remove") > > 93b6604c5a66 ("i2c: Allow recovery of the initial IRQ by an I2C client device.") > > > > > >How should we proceed with this patch? > > > There's also dependency to commit > b9bb3fdf4e87 ("i2c: Remove unnecessary call to irq_find_mapping") > > Without it 93b6604c5a66 doesn't apply. > > Otherwise my patch don't have dependency into these so I can have > another version for 4.19 if needed. > > I got impression from the mail thread for 6f108dd70d30 that it could > be also stable material but cannot really judge. > > Charles: does your commits b9bb3fdf4e87 and 6f108dd70d30 with the > fix 93b6604c5a66 qualify for 4.19? (background: my fix doesn't apply > without them but doesn't depend on them). > b9bb3fdf4e87 ("i2c: Remove unnecessary call to irq_find_mapping") I don't think this one would make sense to backport it's not fixing any issues it just removes a redundant call. The call just repeats work it does no harm. 6f108dd70d30 ("i2c: Clear client->irq in i2c_device_remove") 93b6604c5a66 ("i2c: Allow recovery of the initial IRQ by an I2C client device.") These two are much more of a grey area, they do fix an actual issue, although that issue only happens when you unbind and rebind both an I2C device and the device providing its IRQs. A couple of us have been trying to look for a better fix as well which further complicates matters. I would suggest you just backport your patch and leave these ones. As evidenced by the fixup patch there is a slight chance of regressions from backporting this fix and the issue it fixes is clearly not something people are normally hitting. Thanks, Charles From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93F43C43219 for ; Thu, 2 May 2019 15:33:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F3552081C for ; Thu, 2 May 2019 15:33:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728018AbfEBPdA (ORCPT ); Thu, 2 May 2019 11:33:00 -0400 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:41036 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729291AbfEBPc7 (ORCPT ); Thu, 2 May 2019 11:32:59 -0400 Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x42FOkwL028384; Thu, 2 May 2019 10:32:52 -0500 Authentication-Results: ppops.net; spf=none smtp.mailfrom=ckeepax@opensource.cirrus.com Received: from mail4.cirrus.com ([87.246.98.35]) by mx0a-001ae601.pphosted.com with ESMTP id 2s6xhv34q3-1; Thu, 02 May 2019 10:32:52 -0500 Received: from EDIEX01.ad.cirrus.com (ediex01.ad.cirrus.com [198.61.84.80]) by mail4.cirrus.com (Postfix) with ESMTP id 2ADCD611C8AF; Thu, 2 May 2019 10:34:36 -0500 (CDT) Received: from EDIEX01.ad.cirrus.com (198.61.84.80) by EDIEX01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1591.10; Thu, 2 May 2019 16:32:51 +0100 Received: from ediswmail.ad.cirrus.com (198.61.86.93) by EDIEX01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server id 15.1.1591.10 via Frontend Transport; Thu, 2 May 2019 16:32:51 +0100 Received: from ediswmail.ad.cirrus.com (ediswmail.ad.cirrus.com [198.61.86.93]) by ediswmail.ad.cirrus.com (Postfix) with ESMTP id 5734E44; Thu, 2 May 2019 16:32:51 +0100 (BST) Date: Thu, 2 May 2019 16:32:51 +0100 From: Charles Keepax To: Jarkko Nikula CC: Sasha Levin , , Wolfram Sang , Subject: Re: [PATCH] i2c: Prevent runtime suspend of adapter when Host Notify is required Message-ID: <20190502153251.GG81578@ediswmail.ad.cirrus.com> References: <20190430142322.15013-1-jarkko.nikula@linux.intel.com> <20190430155637.1B45E21743@mail.kernel.org> <7f989564-e994-5be6-02da-2838639efe59@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <7f989564-e994-5be6-02da-2838639efe59@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905020103 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, May 02, 2019 at 03:32:24PM +0300, Jarkko Nikula wrote: > On 4/30/19 6:56 PM, Sasha Levin wrote: > >This commit has been processed because it contains a "Fixes:" tag, > >fixing commit: c5eb1190074c PCI / PM: Allow runtime PM without callback functions. > > > >The bot has tested the following trees: v5.0.10, v4.19.37. > > > >v5.0.10: Build OK! > >v4.19.37: Failed to apply! Possible dependencies: > > 6f108dd70d30 ("i2c: Clear client->irq in i2c_device_remove") > > 93b6604c5a66 ("i2c: Allow recovery of the initial IRQ by an I2C client device.") > > > > > >How should we proceed with this patch? > > > There's also dependency to commit > b9bb3fdf4e87 ("i2c: Remove unnecessary call to irq_find_mapping") > > Without it 93b6604c5a66 doesn't apply. > > Otherwise my patch don't have dependency into these so I can have > another version for 4.19 if needed. > > I got impression from the mail thread for 6f108dd70d30 that it could > be also stable material but cannot really judge. > > Charles: does your commits b9bb3fdf4e87 and 6f108dd70d30 with the > fix 93b6604c5a66 qualify for 4.19? (background: my fix doesn't apply > without them but doesn't depend on them). > b9bb3fdf4e87 ("i2c: Remove unnecessary call to irq_find_mapping") I don't think this one would make sense to backport it's not fixing any issues it just removes a redundant call. The call just repeats work it does no harm. 6f108dd70d30 ("i2c: Clear client->irq in i2c_device_remove") 93b6604c5a66 ("i2c: Allow recovery of the initial IRQ by an I2C client device.") These two are much more of a grey area, they do fix an actual issue, although that issue only happens when you unbind and rebind both an I2C device and the device providing its IRQs. A couple of us have been trying to look for a better fix as well which further complicates matters. I would suggest you just backport your patch and leave these ones. As evidenced by the fixup patch there is a slight chance of regressions from backporting this fix and the issue it fixes is clearly not something people are normally hitting. Thanks, Charles